1. Field of the Invention
The present invention relates to an active array antenna apparatus capable of controlling a radio frequency (RF) polarization in real time, and more particularly, to a general antenna apparatus capable of environmentally and temporally controlling polarization resources necessary for wireless communication in order to improve communication quality and increase communication capacity.
2. Related Art
A wireless terrestrial/satellite communication system generally transmits/receives data information through antennas using a predetermined frequency. Here, as an important element for transmitting and receiving signals in the wireless terrestrial/satellite communication system, antennas are present at an end of the wireless terrestrial/satellite communication system. These antennas should be configured to efficiently transmit and receive electromagnetic waves. Therefore, the research and development of the antenna has been actively conducted.
A significantly number of antennas are present. However, as a generally used high frequency antenna, there are a dipole antenna, a monopole antenna, a patch antenna, a horn antenna, a parabolic antenna, a helical antenna, a slot antenna, and the like. These antenna are applied and used in various forms according to a communication distance and a service area.
As necessary resources of the wireless terrestrial/satellite communication system, there are frequency, polarization, space, and direction. In the present and the future, a frequency resource, which is the most important resource for wireless communication, has been exhausted due to an increase in kinds of wireless communication services. In addition, a multiple input multiple output (MIMO) communication technology has been necessarily demanded due to an increase in bandwidth of a service. An object of this MIMO communication technology is to increase communication capacity by performing independent multi-channel transmission using multiple antennas. However, most satellite communication/mobile communication terminal or relay/base station antennas for MIMO communication have currently used the defined fixed polarization. In this antenna system structure using the fixed polarization, it is expected that service quality is deteriorated to an interference problem between services, or the like, caused by an increase in a service and an increase in a bandwidth in the future. In order to overcome this problem, an antenna technology of improving service quality and increasing service capacity by temporally variably controlling the polarization of the antenna so as to be appropriate for wireless environment and system requirement had been demanded.
In the future, due to saturation (depletion) of the wireless communication, elastic application/utilization of new radio resources such as a polarization, a space, a direction, or the like, has been absolutely required.